Coming just a day after the death of singer Dan Fogelberg at age 56 from the same disease, Nash made the announcement on an episode of CNN's "Larry King Live," during a telephone interview with the host.

"Unlike Danny [Fogelberg], who left it too long to be seriously checked, Stephen found his at an early stage," Nash told King on the show.

According to Nash, Stills is scheduled to undergo surgery to treat the cancer on Jan. 3, which is also the singer's 63rd birthday.

Stills was a member of Buffalo Springfield before forming CS&N in 1968 with former Hollies singer Graham Nash and David Crosby of The Byrds. The trio's self-titled debut album was released the following year and was a commercial success, spawning a pair of Top 40 singles with "Marrakesh Express" and "Suite: Judy Blue Eyes." The trio added former Buffalo Springfield guitarist Neil Young [ tickets ] in 1969, launching a long run of No. 1 albums as a foursome with 1970's "Deja Vu."

Earlier this year, Stills released "Just Roll Tape," a set of 12 long-lost demos from a 1968 recording session. The collection of songs--which finally made its way into Nash's hands in 2003 before he passed it along to Stills--includes the first recordings of songs that would later become classics for Stills and his groups, including "Suite: Judy Blue Eyes," "Helplessly Hoping," "Wooden Ships" and "Change Partners."

Stills was ranked at No. 28 on Rolling Stone's list of "100 Greatest Guitarists of All Time." He is the only artist ever to be inducted into the Rock and Roll Hall of Fame twice in one night--for Buffalo Springfield and Crosby, Stills & Nash [ tickets ].